At a surprise last-minute campaign stop at a Cleveland diner later in the day, the vice president was put on the spot by a voter who asked whether he would make yet another run for the White House in 2016 if President Obama wins.

"Oh, I'm going to go back home and run for county council or something," Biden responded.

But joking aside, Biden has a difficult calculation to make over the next two years, when the race for 2016 truly heats up.

It's perhaps a more serious quandary if Obama is declared the winner of Tuesday's election than not, because the vice president could stake claim to being the rightful Democratic heir to a two-term presidency.

Biden already has made two unsuccessful runs for the presidency, campaigns that were most remarkable for gaffes. In 1988, he ended his bid for the White House after being accused of plagiarizing parts of a stump speech. His brief 2008 run was most memorable for describing Obama as the "first mainstream African-American who is articulate and bright and clean and a nice-looking guy."

He also could face stiff competition for the Democratic nomination. Among names being floated as potential contenders are Secretary of State Hillary Rodham Clinton, New York Gov. Andrew Cuomo and Maryland Gov. Martin O'Malley.

Biden, who started his career in politics 42 years ago when he won a spot on the New Castle (Del.) County Council, will also be facing Father Time.

The vice president turns 70 later this month.

But Biden, who told reporters early Tuesday that he was feeling "pretty good" about his and the president's chances to eke out a win, suggested as hasn't lost his passion for politics.

Vice President Joe Biden and his family voted early Tuesday morning at A.I. duPont High School in Greenville. Biden heads to Ohio for an afternoon of campaigning before arriving in Chicago for tonight's election rally. (11/6/12)

At his Cleveland diner stop, he appeared to relish pressing the flesh, as he has throughout the campaign. He even asked some older, stocky men if they played football and dubbed an enthusiastic group of diners a "power table."

And when a poll worker apologized for the fact that the vice president had to wait to cast a ballot, Biden didn't mind in the least.

Instead he waxed about the joy of being on the ballot.

"I tell you what, you know, every time I do it — this is the eighth time that I've run statewide in the state of Delaware," Biden said after casting his ballot, "it's always a kick, it really is, to see people out here. I hope everybody exercises their right to vote. It's a great honor."